Crystal structures of an unmodified bacterial tRNA reveal intrinsic structural flexibility and plasticity as general properties of unbound tRNAs

Variation in angle of the “elbow” region of tRNAs. The angle of the “elbow” region (made up of the TΨC and D loops) varies from tRNA to tRNA without any obvious correlation to the nucleobase modification status of the entire tRNA molecule, as was previously proposed (Byrne et al. 2010). The figure shows the “elbow” angles calculated from three reference points (ABC) and from the angle formed by the best axes of the two stems (H1–H2; see Materials and Methods).